JP2002036411A - Functional coating film and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a functional coating film which displays various kinds of function by a coating process as well as a manufacturing method therefor. SOLUTION: This functional coating film includes a compressed functional fine particle layer obtained by compressing a layer containing functional fine particles formed on a support by application. The layer containing the functional fine particles is formed by applying and drying a functional fine particle- dispersed liquid on the support. The compressed functional fine particle layer is obtained preferably by compressing the layer with 44 N/mm2 or more compression force and the functional fine particles are preferably selected from among inorganic fine particles. Further, the support is preferably is made of a resin film. For the functional coating film, films such as conducting, magnetic, ferromagnetic, dielectric, ferroelectric, electrochromic, electroluminescene, insulative, photoabsorptive, photoselective/absorptive, reflective, antireflective, catalytic and photocatalytic films are cited.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a functional film and a method for producing the same. In the present invention, the functional film is defined as follows. That is, the functional film is a film having a function, and the function means a function performed through physical and / or chemical phenomena. Functional films include conductive films, magnetic films, ferromagnetic films, dielectric films, ferroelectric films, electrochromic films, electroluminescent films, insulating films, light absorbing films, light selective absorbing films, reflective films, and antireflection films. Films having various functions such as films, catalyst films, and photocatalytic films are included.

[0002] In particular, the present invention relates to a transparent conductive film and a method for producing the same. The transparent conductive film can be used as a transparent electrode such as an electroluminescence panel electrode, an electrochromic element electrode, a liquid crystal electrode, a transparent surface heating element, and a touch panel, and can also be used as a transparent electromagnetic wave shielding film. In particular, the transparent conductive film of the present invention is suitable for applications requiring low scattering, such as a transparent surface heating element and a touch panel.

[0003]

2. Description of the Related Art Conventionally, functional films made of various functional materials have been produced by physical vapor deposition (PVD) such as vacuum deposition, laser ablation, sputtering, ion plating, thermal CVD, optical CVD, and the like. It is manufactured by chemical vapor deposition (CVD) such as plasma CVD. These generally require a large-scale apparatus, and some of them are not suitable for forming a large-area film.

[0004] Further, formation of a film by coating using a sol-gel method is also known. The sol-gel method is also suitable for forming a large-area film, but often requires sintering the inorganic material at a high temperature after coating.

For example, a transparent conductive film is as follows. At present, transparent conductive films are mainly manufactured by a sputtering method. There are various methods of sputtering, for example, accelerated collision of inert gas ions generated by direct current or high-frequency discharge in a vacuum onto the target surface, and strike out atoms constituting the target from the surface,
This is a method of forming a film by depositing it on the substrate surface. The sputtering method is excellent in that a conductive film having a low surface electric resistance can be formed even with a relatively large area. However, there is a disadvantage that the apparatus is large and the film forming speed is low. As the area of the conductive film is further increased in the future, the size of the device will be further increased. This technically causes problems such as the necessity of increasing control accuracy, and another problem arises that manufacturing costs increase.
Further, the number of targets is increased to compensate for the low film formation speed, and the speed is increased. However, this also causes a problem in that the size of the apparatus is increased.

[0006] Production of a transparent conductive film by a coating method has also been attempted. In a conventional coating method, a conductive paint in which conductive fine particles are dispersed in a binder solution is applied on a substrate, dried, and cured to form a conductive film. The coating method has such advantages that a large-area conductive film can be easily formed, the apparatus is simple, the productivity is high, and the conductive film can be manufactured at lower cost than the sputtering method. In the coating method, the conductive fine particles come into contact with each other to form an electric path, thereby exhibiting conductivity. However, a conductive film produced by a conventional coating method has a defect that the contact is insufficient and the resulting conductive film has a high electric resistance value (poor in conductivity), and its use is limited.

As a method for producing a transparent conductive film by a conventional coating method, for example, Japanese Patent Application Laid-Open No. 9-109259 discloses that a paint comprising a conductive powder and a binder resin is coated on a transfer plastic film, dried, and dried. First step of forming a layer, pressurizing the conductive layer surface to a smooth surface (5 to 100 kg /
cm ² ), a second step of heating (70 to 180 ° C.)
A production method comprising a third step of laminating this conductive layer on a plastic film or sheet and thermocompression bonding is disclosed. In this method, a large amount of binder resin is used (in the case of inorganic conductive powder, binder 1 is used).
100 parts by weight, 100 to 500 parts by weight of conductive powder, and in the case of organic conductive powder, 0.1 to 30 parts by weight of conductive powder with respect to 100 parts by weight of binder)
A transparent conductive film having a low electric resistance cannot be obtained.

For example, Japanese Patent Application Laid-Open No. 8-199096 discloses a method for forming a binder-free conductive film comprising tin-doped indium oxide (ITO) powder, a solvent, a coupling agent, and an organic or inorganic acid salt of a metal. A method is disclosed in which a paint is applied to a glass plate and fired at a temperature of 300 ° C. or higher. In this method, since no binder is used, the electric resistance of the conductive film is reduced. But 300 ° C
Since it is necessary to perform the firing step at the above temperature, it is difficult to form a conductive film on a support such as a resin film. That is, the resin film is melted, carbonized, or burned by the high temperature. Depending on the type of resin film, for example, polyethylene terephthalate (P
For ET) films, a temperature of 130 ° C. would be the limit.

Japanese Patent No. 2994764 discloses a transparent method comprising applying a paste obtained by dispersing an ultrafine powder of ITO in a solvent together with a resin to a resin film, drying the paste, and then performing a rolling treatment with a steel roll. A method for manufacturing a conductive film is disclosed.

Japanese Patent Application Laid-Open No. Hei 7-235220 discloses an IT
A dispersion liquid containing conductive fine particles such as O and containing no binder is applied on a glass substrate, dried slowly, and an overcoat liquid composed of silica sol is applied on the obtained ITO film, and then dried or dried. A method for performing subsequent firing is disclosed. According to the publication, an overcoat film made of silica sol is dried and contracted by curing, and the fine particles of ITO in the ITO film are brought into firm contact with each other by the curing contraction stress at that time. If the contact between the ITO fine particles is insufficient, the electric resistance of the conductive film is high. In order to obtain a large curing shrinkage stress, overcoat film
It is necessary to carry out a drying treatment at a high temperature of 80 ° C. However, when the support is a resin film, the resin film is deformed by such a high temperature. According to the same publication, the overcoat made of silica sol also contributes to the bonding between the conductive film and the glass substrate. That is, the strength of the conductive film is obtained by the overcoat made of silica sol. However, if the application of the overcoat solution and the curing shrinkage are not performed, the electric resistance of the conductive film is high and the strength of the film is low. Further, in order to improve the optical properties of the conductive film and reduce the surface resistance, it is necessary to slowly dry the dispersion of the conductive fine particles after applying the dispersion to the glass substrate. The overcoat film made of silica sol has a disadvantage that cracks occur when the film thickness is large.

As a method other than the coating method, see Japanese Patent Application Laid-Open No.
Japanese Patent No. 3785 discloses a powder compression layer in which at least a part, preferably all of the voids of a skeleton structure composed of a conductive substance (metal or alloy) powder is filled with a resin, and a resin under the powder compressed layer. A conductive coating comprising a layer is disclosed.
The production method will be described by taking a case where a film is formed on a plate material as an example. According to the publication, first, a resin, a powdery substance (metal or alloy) and a plate material to be processed are vibrated or agitated in a container together with a film forming medium (steel balls having a diameter of several mm). A resin layer is formed on the surface. Subsequently, the powder material is captured and fixed to the resin layer by the adhesive force of the resin layer. Further, the vibrating or agitating film-forming medium exerts a striking force on the vibrating or agitating powder material to form a powder compaction layer. A significant amount of resin is required to obtain the effect of fixing the powder compression layer. Further, the production method is more complicated than the coating method.

As a method other than the coating method, see JP-A-9-19-1
JP-A-07195 discloses a method in which conductive short fibers are sprinkled and deposited on a film such as PVC, and this is subjected to a pressure treatment to form a conductive fiber-resin integrated layer. The conductive short fiber is a short fiber such as polyethylene terephthalate, which is coated with nickel plating or the like. The pressing operation is preferably performed under a temperature condition at which the resin matrix layer shows thermoplasticity.
High temperature and low pressure conditions of g / cm ² are disclosed.

[0013]

From such a background,
A functional film that can easily form a large-area functional film, is simple to use, has high productivity, and can produce a functional film at a low cost. Development of the resulting method is desired.

Particularly, regarding the conductive film, a large-area conductive film can be easily formed, the apparatus is simple, and the productivity is high.
It is desired to develop a method for obtaining a transparent conductive film having a low electric resistance value while taking advantage of the application method that a conductive film can be manufactured at low cost.

Accordingly, it is an object of the present invention to provide a functional film capable of exhibiting various functions by a coating method, and to provide a method of manufacturing the functional film by a coating method.

In particular, it is an object of the present invention to provide a transparent conductive film having a low resistance value and preferably less scattering by a coating method, and to provide a method for producing the transparent conductive film by a coating method. Further, the present invention provides a method for producing a transparent conductive film capable of forming a film without requiring a high-temperature heating operation and obtaining a film having a uniform and uniform thickness, and a method for producing a transparent conductive film capable of coping with a large area of the film. Is to do.

[0017]

Means for Solving the Problems Conventionally, in a coating method,
If a large amount of binder resin is not used, a functional film cannot be formed, or if no binder resin is used,
It was thought that a functional film could not be obtained unless the functional material was sintered at a high temperature. Regarding the conductive film, a conductive film cannot be formed unless a large amount of the binder resin is used, or if the binder resin is not used, the conductive film cannot be obtained unless the conductive material is sintered at a high temperature. Was considered.

However, as a result of intensive studies, the present inventor has found that
Surprisingly, it was found that a functional film having mechanical strength and capable of exhibiting various functions can be obtained by compression without using a large amount of binder resin and without firing at a high temperature. The invention has been reached. The present inventors have found that a transparent conductive film having a low resistance value can be obtained by using a conductive substance, and have reached the present invention.

The present invention is a functional film in which a functional fine particle-containing coating layer is formed on a support. The present invention is a functional film including a compressed layer of functional fine particles obtained by compressing a layer containing functional fine particles formed by coating on a support. The functional fine particle-containing layer is formed by applying a liquid in which functional fine particles are dispersed on a support and drying the liquid.

In the functional film, the functional fine particles are preferably selected from inorganic fine particles. In the functional film, the compressed layer of the functional fine particles has a thickness of 44 N / m.
It is preferably obtained by compressing with a compression force of m ² or more.

The functional film includes, for example, a conductive film, a magnetic film, a ferromagnetic film, a dielectric film, a ferroelectric film, an electrochromic film, an electroluminescent film, an insulating film, a light absorbing film, a light selective absorbing film, It is selected from a reflection film, an antireflection film, a catalyst film and a photocatalyst film.

In the functional film, the support is preferably a resin film.

In particular, the present invention relates to a transparent conductive film.
When the functional film is a conductive film, the functional fine particles are conductive fine particles and have a function as a conductive film. That is, the present invention is a transparent conductive film including a compressed layer of conductive fine particles obtained by compressing a layer containing conductive fine particles formed by coating on a support. In this case,
Examples of the conductive fine particles include tin oxide, indium oxide, zinc oxide, cadmium oxide, antimony-doped tin oxide (ATO), fluorine-doped tin oxide (FTO), tin-doped indium oxide (ITO), and aluminum-doped zinc oxide (AZO). ) Are preferably selected from the group consisting of conductive inorganic fine particles.

The present invention also provides a method in which a liquid in which functional fine particles are dispersed is coated on a support and dried to form a layer containing functional fine particles. A method for producing a functional film, comprising forming a compression layer.

In the above method, it is preferable that the functional fine particle-containing layer is compressed with a compressive force of 44 N / mm ² or more. In the method, the functional fine particle-containing layer is preferably compressed at a temperature at which the support does not deform.
In the above method, the functional fine particle-containing layer is preferably compressed using a roll press.

When the functional film is a conductive film, conductive fine particles are used as the functional fine particles. That is, the present invention applies a liquid in which conductive fine particles are dispersed on a support,
A method for producing a transparent conductive film, comprising drying, forming a layer containing conductive fine particles, and thereafter compressing the layer containing conductive fine particles to form a compressed layer of conductive fine particles. In the above method, the dispersion of the conductive fine particles may contain a small amount of resin, but it is particularly preferable that the dispersion contains no resin.

In particular, in the present invention, a transparent conductive material is impregnated in a compressed layer of the conductive fine particles as the functional fine particles, thereby providing a transparent conductive film having a low resistance value and a small scattering.

That is, the present invention relates to a transparent conductive film including a compressed layer of conductive fine particles obtained by compressing a layer containing conductive fine particles formed by coating on a support, wherein The compression layer is a transparent conductive film impregnated with a transparent substance.

Further, according to the present invention, a liquid in which conductive fine particles are dispersed is coated on a support and dried to form a conductive fine particle-containing layer. Thereafter, the conductive fine particle-containing layer is compressed to form a conductive fine particle-containing layer. A method for producing a transparent conductive film, comprising: forming a compressed layer of (i), and further impregnating the formed compressed layer of conductive fine particles with a transparent substance.

[0030]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a functional film includes
Without being particularly limited, a conductive film, a magnetic film, a ferromagnetic film,
Films having various functions such as a dielectric film, a ferroelectric film, an electrochromic film, an electroluminescence film, an insulating film, a light absorption film, a light selective absorption film, a reflection film, an antireflection film, a catalyst film, and a photocatalyst film. included. Therefore, in the present invention, the functional fine particles that constitute the target film are used. The functional fine particles are not particularly limited, and mainly inorganic fine particles having a cohesive force are used. In the production of any functional film, by applying the method of the present invention, a functional coating film having sufficient mechanical strength can be obtained, and a binder in a conventional coating method using a large amount of a binder resin. The adverse effects of the resin can be eliminated. As a result, the intended function is further improved.

For example, in the production of a transparent conductive film, tin oxide, indium oxide, zinc oxide, cadmium oxide, antimony-doped tin oxide (ATO), fluorine-doped tin oxide (FTO), tin-doped indium oxide (ITO), aluminum Conductive inorganic fine particles such as doped zinc oxide (AZO) are used. Alternatively, organic conductive fine particles may be used. By applying the present manufacturing method, excellent conductivity can be obtained.

In the production of a ferromagnetic film, γ-Fe ₂ O
₃ , iron oxide-based magnetic powders such as Fe ₃ O ₄ , Co—FeOx, and Ba ferrite, α-Fe, Fe—Co, Fe—N
i, a ferromagnetic alloy powder containing a ferromagnetic metal element such as Fe-Co-Ni, Co, or Co-Ni as a main component is used.
By applying this manufacturing method, the saturation magnetic flux density of the magnetic coating film is improved.

In the production of a dielectric film or a ferroelectric film,
Magnesium titanate, barium titanate, strontium titanate, lead titanate, lead zirconate titanate (PZT), lead zirconate, lanthanum-added lead zirconate titanate (PLZT), magnesium silicate Fine particles of a dielectric or ferroelectric material such as a system and a lead-containing perovskite compound are used. By applying the present manufacturing method, the dielectric characteristics or the ferroelectric characteristics can be improved.

In manufacturing a metal oxide film exhibiting various functions, iron oxide (Fe ₂ O ₃ ), silicon oxide (SiO ₂ )
₂ ), aluminum oxide (Al ₂ O ₃ ), titanium dioxide (TiO ₂ ), titanium oxide (TiO), zinc oxide (Zn)
Fine particles of metal oxides such as O), zirconium oxide (ZrO ₂ ), and tungsten oxide (WO ₃ ) are used. By applying this manufacturing method, the degree of filling of the metal oxide in the film is increased, and each function is improved. For example, when SiO ₂ or Al ₂ O ₃ supporting a catalyst is used, a porous catalyst film having practical strength can be obtained. When TiO ₂ is used, the photocatalytic function can be improved. In addition, WO
_{When 3} is used, an improvement in the coloring effect in the electrochromic display element can be obtained.

In the production of the electroluminescence film, zinc sulfide (ZnS) fine particles are used.
By applying this manufacturing method, an inexpensive electroluminescent film can be manufactured by a coating method.

In the present invention, a liquid in which functional fine particles selected from the above various functional fine particles are dispersed according to the purpose is used as a functional paint. This functional paint is applied on a support and dried to form a layer containing functional fine particles. Thereafter, the layer containing the functional fine particles is compressed to form a compressed layer of the functional fine particles to obtain a functional film.

The liquid in which functional fine particles such as conductive fine particles are dispersed is not particularly limited, and various known liquids can be used. For example, as a liquid, saturated hydrocarbons such as hexane, aromatic hydrocarbons such as toluene and xylene, alcohols such as methanol, ethanol, propanol and butanol, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and diisobutyl ketone , Ethyl acetate, esters such as butyl acetate, ethers such as tetrahydrofuran, dioxane, diethyl ether, N, N-dimethylformamide;
Examples include amides such as N-methylpyrrolidone (NMP) and N, N-dimethylacetamide, and halogenated hydrocarbons such as ethylene chloride and chlorobenzene. Among these, a liquid having polarity is preferable,
Especially alcohols such as methanol and ethanol, NMP
Those having an affinity for water, such as amides, have good dispersibility even without using a dispersant, and are suitable. These liquids can be used alone or in combination of two or more. Further, a dispersant can be used depending on the type of the liquid.

Further, water can be used as the liquid.
When water is used, the support needs to be hydrophilic. Since the resin film is usually hydrophobic, it easily repels water, and it is difficult to obtain a uniform film. When the support is a resin film, it is necessary to mix alcohol with water or to make the surface of the support hydrophilic.

The amount of the liquid used is not particularly limited as long as the dispersion of the fine particles has a viscosity suitable for a coating method described later. For example, the liquid is about 100 to 100,000 parts by weight based on 100 parts by weight of the fine particles. It may be appropriately selected according to the types of the fine particles and the liquid. Generally, as the particle size of the fine particles decreases, the specific surface area increases, and the viscosity tends to increase. When fine particles having a large specific surface area are used, the amount of the liquid may be increased to lower the solid content concentration. Even when the thickness of the coating film is small, it is preferable to increase the amount of the liquid and use a coating liquid having a low solid content concentration.

The fine particles may be dispersed in the liquid by a known dispersion technique. For example, the particles are dispersed by a sand grinder mill method. At the time of dispersion, it is also preferable to use a medium such as zirconia beads in order to loosen the aggregation of the fine particles. At the time of dispersion, care should be taken not to mix impurities such as dust.

It is preferable that the dispersion liquid of the fine particles does not contain a resin. That is, it is preferable that the resin amount = 0. If the dispersion liquid of the fine particles does not contain a resin, the functional fine particle-containing layer (before compression) formed by coating does not contain the resin.

In the conductive film, if no resin is used,
The resin does not hinder contact between the conductive fine particles. Therefore, conductivity between the conductive fine particles is ensured, and the obtained conductive film has a low electric resistance value. It is possible to include a resin as long as the conductivity is not impaired, but the amount is very small as compared with the amount used as a binder resin in the prior art. For example, the upper limit of the content of the resin in the dispersion is represented by the volume before dispersion,
When the volume of the conductive fine particles is 100, the volume is about 19. In the prior art, strong compression was not performed, so that a large amount of binder had to be used to obtain the mechanical strength of the coating film. If the resin is used in such an amount that it plays a role as a binder, contact between the conductive fine particles is hindered by the binder, electron transfer between the fine particles is hindered, and the conductivity is reduced. From the viewpoint of obtaining high conductivity, the content of the resin in the dispersion liquid should be less than 3.7 when the volume of the conductive fine particles is represented by the volume before dispersion and the volume of the conductive fine particles is 100. And a volume of 0 is particularly preferred.

Even in a functional film using other functional fine particles such as WO ₃ fine particles and TiO ₂ fine particles, if no resin is used, contact between the fine particles is not hindered by the resin. The function is improved.
As long as the contact between the fine particles is not hindered and the respective functions are not impaired, it is possible to include a resin, but the amount is, for example, about 80 or less when the volume of each fine particle is 100. Volume, preferably a volume of 19 or less.

In a catalyst film using Al ₂ O ₃ fine particles or the like, if no resin is used, the surface of the fine particles having a catalytic function is not covered with the resin. For this reason,
The function as a catalyst is improved. In the catalyst film, the more voids inside the film, the more active sites as a catalyst, and from this viewpoint, it is preferable to use no resin.

As described above, it is preferable that no resin is used for the functional film at the time of compression (that is, in the dispersion of the functional fine particles), and even if it is used, a small amount is preferable. The amount of the resin used may vary to some extent depending on the purpose of the functional film, and may be appropriately determined.

Various additives may be added to the dispersion of the fine particles as long as the performance required for each function such as conductivity and catalysis is satisfied. For example, ultraviolet absorbers,
It is an additive such as a surfactant and a dispersant.

The support is not particularly limited, and may be a resin film, glass, ceramics, metal, cloth,
Various materials such as paper can be used. However, in the case of glass, ceramics, and the like, it is highly likely that the glass will be broken at the time of compression in a later step, and therefore it is necessary to consider this point. The shape of the support may be a film, a foil, a mesh, a fabric, or the like.

As the support, a resin film which does not break even when the compression force in the compression step is increased is preferable. As described below, the resin film is also preferable in that it has good adhesion of a layer of functional fine particles such as conductive fine particles to the film, and is also suitable for applications requiring light weight. In the present invention, a resin film can be used as a support because there is no pressurizing step at a high temperature or a firing step. Examples of the resin film include a polyester film such as polyethylene terephthalate (PET), a polyolefin film such as polyethylene or polypropylene, a polycarbonate film, an acrylic film, and a norbornene film (arton, manufactured by JSR Corporation).
And the like.

In a resin film such as a PET film, a part of functional fine particles such as conductive fine particles which are in contact with the PET film during the compression step after drying is partially removed.
It feels like it is embedded in the film, and this fine particle layer adheres well to the PET film.

In the case of a hard material such as glass, or a resin film having a hard film surface, the fine particles are not embedded, so that the adhesion between the fine particle layer and the support cannot be obtained. In that case, it is preferable that a soft resin layer is formed in advance on a glass surface or a hard film surface, and then fine particles are applied, dried, and compressed. After the compression, the soft resin layer may be cured by heat, ultraviolet light, or the like.

It is preferable that the soft resin layer does not dissolve in the liquid in which the fine particles are dispersed. In the conductive film, when the resin layer is dissolved, a solution containing the resin comes around the conductive fine particles due to a capillary phenomenon, and as a result, the electric resistance value of the obtained conductive film increases. Also in the catalyst film, the solution containing the resin comes around the fine particles having the catalytic function due to the capillary phenomenon, and the catalytic function is reduced.

When a hard metal is used as the support, the adhesion between the fine particle layer and the support is poor. Therefore, the surface of the support metal may be treated with a resin or a soft metal (may be an alloy). .

The dispersion of the fine particles is coated on the support and dried to form a layer containing functional fine particles such as a layer containing conductive fine particles. The application of the fine particle dispersion on the support can be performed by a known method without any particular limitation. For example, the application of a dispersion having a high viscosity of 1000 cps or more can be performed by a coating method such as a blade method or a knife method. The low-viscosity dispersion liquid of less than 500 cps can be applied by a coating method such as a bar coating method, a kiss coating method, a squeezing method, or the dispersion liquid can be applied to a support by spraying or spraying. It is. Furthermore, regardless of the viscosity of the dispersion,
Coating methods such as a reverse roll method, a direct roll method, an extrusion nozzle method, a curtain method, a gravure roll method, and a dip method can also be used.

The drying temperature depends on the type of liquid used for dispersion, but is preferably about 10 to 150 ° C. If the temperature is lower than 10 ° C., dew condensation of moisture in the air tends to occur, and if the temperature exceeds 150 ° C., the resin film support is deformed. At the time of drying, care is taken so that impurities do not adhere to the surface of the fine particles.

The thickness of the functional fine particle-containing layer such as the conductive fine particle-containing layer after coating and drying is determined by the compression conditions in the next step and the application of each functional film such as a conductive film finally obtained after compression. Although it depends, it may be about 0.1 to 10 μm.

As described above, when the functional fine particles such as the conductive fine particles are dispersed in a liquid, applied, and dried, a uniform film can be easily formed. When the dispersion of the fine particles is applied and dried, the fine particles form a film even when the binder is not present in the dispersion. Although the reason for forming a film without the presence of a binder is not always clear, fine particles gather together due to capillary force when the liquid is dried and the amount of liquid decreases. Furthermore, the fact that the particles are fine particles has a large specific surface area and a strong cohesive force, so it is thought that they may become a film. However, the strength of the film at this stage is weak. Further, the resistance value of the conductive film is high, and the variation in the resistance value is large.

Next, the formed layer containing functional fine particles such as the layer containing conductive fine particles is compressed to obtain a compressed layer of functional fine particles such as conductive fine particles. The compression improves the strength of the film. That is, by compressing, the number of contact points between functional fine particles such as conductive fine particles increases, and the contact surface increases. For this reason, the strength of the coating film increases. Since the fine particles originally have a property of easily aggregating, they become a strong film by being compressed.

In the conductive film, the strength of the coating increases and the electrical resistance decreases. The catalyst film becomes a porous film because the strength of the coating film is increased and the resin is not used or the amount of the resin is small. Therefore, a higher catalytic function can be obtained. In other functional films, a high strength film in which fine particles are connected to each other can be obtained, and the amount of fine particles per unit volume increases because no resin is used or the amount of resin is small. Therefore, higher functions can be obtained.

The compression is preferably performed with a compression force of 44 N / mm ² or more. If the pressure is lower than 44 N / mm ² ,
A layer containing functional fine particles such as a layer containing conductive fine particles cannot be sufficiently compressed, and it is difficult to obtain a functional film such as a conductive film having excellent functions such as conductivity. 138 N / mm ²
The above compression force is more preferable, and the compression force of 183 N / mm ² is even more preferable. The higher the compressive force, the higher the strength of the coating film and the better the adhesion to the support. In conductive films,
A film having more excellent conductivity is obtained, the strength of the conductive film is improved, and the adhesion between the conductive film and the support becomes strong. Since the higher the compressive force, the higher the pressure resistance of the device must be increased, a compressive force of up to 1000 N / mm ² is generally appropriate.

Preferably, the compression is performed at a temperature at which the support does not deform. For example, when the support is a resin film, the temperature range is equal to or lower than the glass transition temperature (secondary transition temperature) of the resin. When the support is made of metal, the temperature range is such that the metal does not melt.

The compression can be performed without any particular limitation by a sheet press, a roll press or the like, but is preferably performed using a roll press machine. The roll press is a method of sandwiching a film to be compressed between rolls, compressing the roll, and rotating the roll. A roll press is uniformly applied with a high pressure, and is more preferable in productivity than a sheet press and is suitable.

The roll temperature of the roll press machine is preferably room temperature (an environment where humans can easily work) from the viewpoint of productivity. In a heated atmosphere or in a compression (hot press) in which a roll is heated, when the compression pressure is increased, a problem such as the resin film being elongated occurs. If the compression pressure is reduced to prevent the resin film of the support from stretching under heating, the mechanical strength of the coating film decreases. In a conductive film, the mechanical strength of the coating film decreases, and the electrical resistance increases. It is also preferable to adjust the temperature so that the roll temperature does not rise due to heat generation when continuously compressed by a roll press.

When there is a reason that it is desired to minimize the adhesion of moisture on the surface of the fine particles, a heated atmosphere may be used in order to lower the relative humidity of the atmosphere.
The temperature range is such that the film does not easily stretch. Generally, the temperature is lower than the glass transition temperature (secondary transition temperature). The temperature may be set slightly higher than the temperature at which the required humidity is obtained in consideration of fluctuations in humidity. If the support is made of metal, the atmosphere can be heated up to a temperature range in which the metal does not melt.

The glass transition temperature of the resin film is
It is determined by measuring dynamic viscoelasticity and refers to the temperature at which the mechanical loss of the main dispersion peaks. For example, looking at a PET film, its glass transition temperature is around 110 ° C.

The roll of the roll press machine is preferably a metal roll because a strong pressure is applied. In addition, if the roll surface is soft, fine particles may be transferred to the roll during compression. Therefore, the roll surface is hard chromium, ceramic sprayed film, film obtained by ion plating such as TiN, DLC (diamond-like carbon), etc. It is preferable to treat with a hard film.

Thus, a compressed layer of functional fine particles such as conductive fine particles is formed. The thickness of the compressed layer of functional fine particles such as conductive fine particles depends on the application.
The thickness may be about 10 to 10 μm, preferably 0.1 to 5 μm, more preferably 0.1 to 3 μm, and most preferably 0.1 to 2 μm.

Further, in order to obtain a compressed layer having a thickness of about 10 μm, a series of operations of application, drying and compression of the dispersion liquid of fine particles may be repeated. Further, in the present invention, it is of course possible to form each functional film such as a conductive film on both surfaces of the support.

Each functional film such as a transparent conductive film thus obtained exhibits excellent functions such as excellent conductivity and catalytic action, and does not use a binder resin or has such a small amount that it does not function as a binder. Despite the use of the above resin, it has practically sufficient film strength and excellent adhesion to the support.

Next, an example in which the present invention is applied to a transparent conductive film will be described. In the present invention, a liquid in which conductive fine particles are dispersed is used as a conductive paint. This conductive paint is applied on a support and dried to form a layer containing conductive fine particles. Thereafter, the layer containing the conductive fine particles is compressed to form a compressed layer of the conductive fine particles to obtain a conductive film. Further, preferably, the formed compressed layer of the conductive fine particles is impregnated with a transparent substance.

The conductive fine particles in the transparent conductive film are not particularly limited as long as they do not significantly impair the transparency of the conductive film, and inorganic conductive fine particles are used. Alternatively, organic conductive fine particles may be used.

In the present invention, “transparent” means that visible light is transmitted. Regarding the degree of light scattering, the required level differs depending on the use of the conductive film. In the present invention,
In general, there are scattering materials which are generally called translucent. However, when the transparent substance is impregnated into the compressed layer of the conductive fine particles, the conductive film of the present invention has a very low degree of light scattering and excellent transparency.

Examples of the inorganic conductive fine particles include tin oxide,
Indium oxide, zinc oxide, cadmium oxide, etc.
Fine particles such as antimony-doped tin oxide (ATO), fluorine-doped tin oxide (FTO), tin-doped indium oxide (ITO), and aluminum-doped zinc oxide (AZO) are preferred. Further, ITO is preferable in that more excellent conductivity can be obtained. Alternatively, a material in which an inorganic material such as ATO or ITO is coated on the surface of transparent fine particles such as barium sulfate can be used. The particle diameter of these fine particles varies depending on the degree of scattering required according to the application of the conductive film, and cannot be said unconditionally depending on the shape of the particles, but is generally 10 μm or less, preferably 1.0 μm or less, 5 nm-100 nm is more preferable.

As the organic conductive fine particles, for example,
A material in which a metal material is coated on the surface of a resin fine particle is exemplified.

When a resin is contained in the conductive paint, the resin has an effect of reducing scattering of the conductive film. However, in the present invention, as described below, after forming the compressed layer of the conductive fine particles, preferably, the transparent layer is impregnated with the transparent substance, so that scattering of the conductive film is greatly reduced. Therefore, it is not necessary to include a resin in the dispersion liquid of the fine particles.

In the present invention, preferably, the obtained compressed layer of conductive fine particles is impregnated with a transparent substance. Since the obtained compressed layer of conductive fine particles is a porous film, light scattering may occur. Light scattering can be reduced by impregnating the transparent material into the compression layer. Unlike the case where a transparent substance is added to a dispersion of conductive fine particles from the beginning to form a compressed layer containing a transparent substance, a compressed layer of conductive fine particles having low electric resistance is formed, and then a gap is formed between the compressed layers. Since the transparent material is impregnated, the electrical resistance of the resulting conductive film remains low.

In the present invention, “impregnating with a transparent substance” means that an impregnating liquid containing a transparent substance (or a precursor thereof) is impregnated into a gap between compressed layers of porous conductive fine particles, and then impregnated by an appropriate method. Solidifying the transparent material. Alternatively, depending on the use of the conductive film, the impregnated liquid may exist as it is.

The transparent substance to be impregnated is not particularly limited, and includes substances such as organic polymers, organic polymer intermediates, oligomers and monomers. Specifically, fluoropolymer, silicone resin, acrylic resin,
Polyvinyl alcohol, carboxymethyl cellulose,
Organic polymers such as hydroxypropyl cellulose, regenerated cellulose, diacetyl cellulose, polyvinyl chloride, polyvinylpyrrolidone, polyethylene, polypropylene, SBR, polybutadiene, polyethylene oxide, polyester, and polyurethane are exemplified. Precursors (monomer, oligomer) of these organic polymers may be impregnated and converted into these organic polymers by performing an ultraviolet treatment or a heat treatment after the impregnation. In addition, as long as it can be made liquid at the time of impregnation, an inorganic substance, glass, or the like can be used. When the temperature of the impregnating liquid is high, it is preferable to use a support that is not easily affected by the high temperature.

When a resin film is used as the support, an inorganic material that can be formed at a low temperature that does not affect the resin film of the support can be used as the transparent material to be impregnated. For example, titanium peroxide, tungsten peroxide, or the like can be used. An impregnating solution obtained by dissolving titanium peroxide in water is applied on the compression layer, and the water is dried and heat-treated at about 100 ° C. to obtain titanium oxide. A metal alkoxide solution may be applied by a sol-gel method and heat-treated at about 100 ° C. to form a metal oxide. Polysilazane may be used. Further, a liquid such as silicone oil may be impregnated. The transparent material to be impregnated does not necessarily have the property of curing shrinkage, and can be selected from a wide range of transparent materials. When a metal or ceramics is used as the support, it may be impregnated with molten glass.

The impregnating liquid can be obtained by dissolving a transparent substance or its precursor in a suitable solvent. The solvent is not particularly limited, and various known liquids can be used. For example, saturated hydrocarbons such as hexane, aromatic hydrocarbons such as toluene and xylene, alcohols such as methanol, ethanol, propanol and butanol, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and diisobutyl ketone, and ethyl acetate , Esters such as butyl acetate, tetrahydrofuran, dioxane, ethers such as diethyl ether,
Examples include amides such as N, N-dimethylformamide, N-methylpyrrolidone (NMP) and N, N-dimethylacetamide, halogenated hydrocarbons such as ethylene chloride and chlorobenzene, and water. It is preferable to adjust the viscosity of the impregnating liquid so that the impregnation is easy.

If the transparent substance or its precursor is a liquid such as a monomer or an oligomer, the transparent substance or its precursor can be used as it is as an impregnating liquid without dissolving in a solvent. . Alternatively, an impregnating solution may be prepared by diluting with an appropriate solvent so as to facilitate impregnation.

The impregnating liquid may contain various additives. For example, additives such as an ultraviolet absorber, an infrared absorber, and a coloring agent.

The transparent substance can be impregnated by applying the impregnating liquid to the surface of the compressed layer of conductive fine particles, or by dipping the compressed layer in the impregnating liquid. Since the compression layer is porous, the impregnating liquid enters the gap by capillary force.

The application of the impregnating liquid to the compressed layer of the conductive fine particles is not particularly limited, and can be performed by a known method. For example, it can be performed by a coating method such as a reverse roll method, a direct roll method, a blade method, a knife method, an extrusion nozzle method, a curtain method, a gravure roll method, a bar coat method, a dip method, a kiss coat method, and a squeeze method. Further, it is also possible to cause the impregnating liquid to adhere to and impregnate the compressed layer by spraying, spraying, or the like.

After the impregnating liquid is impregnated into the gaps of the compressed layer, the transparent substance impregnated by an appropriate method is solidified. For example, a method of drying a solvent after impregnation to solidify a transparent substance, a method of drying a solvent after impregnation and curing an organic polymer and / or monomer and / or oligomer by ultraviolet treatment or heat treatment, and a method of curing a metal peroxide after impregnation. A method in which a metal alkoxide is heat-treated at a temperature up to about 100 ° C. to form a metal oxide may be applied. An appropriate method is adopted depending on the transparent material used.

The application amount of the impregnating liquid on the compressed layer of the conductive fine particles is appropriately selected according to the use of the conductive film.
For example, when the entire surface of the conductive film is to be brought into an electrically contactable state, it is preferable to set the application amount to fill the gap between the compression layers. A protective layer of a transparent substance may be formed on the compressed layer at the same time as the impregnation so that the coating amount is such that the gap between the compressed layers is filled. In this case, the thickness of the protective layer is generally about 0.1 μm to 100 μm. It is preferable to select the amount of the impregnating liquid applied according to the thickness of the protective layer.

When a conductive portion is desired to be left at a desired portion (usually an end portion) of the surface of the conductive film, a portion where the protective layer is not formed may be secured by a masking process or the like. Alternatively, after forming the protective layer, a part of the protective layer may be removed.

By the impregnation of such a transparent substance, scattering of light on the surface of the compressed layer of the conductive fine particles is reduced.

[0088]

EXAMPLES The present invention will be described more specifically with reference to the following examples, but the present invention is not limited to these examples. Examples 1 to 6 and Comparative Example 1 are examples in which ATO fine particles are used as conductive fine particles in order to obtain a transparent conductive film for use in shielding CRT electromagnetic waves.

[Example 1] ATO fine particles having a primary particle size of 10 to 30 nm (SN-100P: manufactured by Ishihara Sangyo Co., Ltd.) 1
300 parts by weight of ethanol was added to 00 parts by weight, and the medium was dispersed as zirconia beads with a disperser. The obtained coating liquid was applied on a PET film having a thickness of 50 μm using a bar coater, and dried by sending warm air at 50 ° C. The resulting film is hereinafter referred to as the pre-compression ATO film. The thickness of the ATO-containing coating film was 1.7 μm.

First, a preliminary experiment for confirming the compression pressure was performed. Room temperature (23 ° C.) using a roll press equipped with a pair of 140 mm-diameter metal rolls (having a roll surface subjected to hard chrome plating) without rotating the rolls and without heating the rolls Compressed the ATO film before compression. At this time, the pressure per unit length in the film width direction was 1000 N / mm. Next, the pressure was released, and the length of the compressed portion in the longitudinal direction of the film was 2 mm. From this result, it can be understood that compression was performed at a pressure of 500 N / mm ² per unit area.

Next, the same pre-compression ATO film as that used in the preliminary experiment was sandwiched between metal rolls and compressed under the above conditions, and the rolls were rotated and compressed at a feed speed of 5 m / min. Thus, a compressed ATO film was obtained. The thickness of the ATO coating film after compression was 1.0 μm.

(Electrical Resistance) The film on which the conductive film was formed was cut into a size of 50 mm × 50 mm. A tester was applied to two diagonal corners to measure the electric resistance, and it was 65 kΩ.

(90 degree peel test) To evaluate the adhesion of the conductive film to the support film and the strength of the conductive film,
A peel test was performed. This will be described with reference to FIG. In the test sample (1) on which the conductive film was formed, a double-sided tape (2) was attached to the surface of the support film (1b) opposite to the surface on which the conductive film (1a) was formed. This is 25mm x 100
mm. Test sample (1) on stainless steel plate
Pasted in (3). To prevent the test sample (1) from peeling off,
Cellophane adhesive tape (width 12 mm, manufactured by Nitto Denko No. 29) (4) was applied to both ends (25 mm side) of the sample (1). (FIG. 1 (a)).

Cellophane adhesive tape (width 12 mm, No. 29, manufactured by Nitto Denko) was applied to the conductive film (1a) surface of the test sample (1) (5)
Was attached so as to be parallel to the long side of the sample (1). Cellophane tape (5) and sample (1) are 50 m long
m. The end of the cellophane tape (5) to which the cellophane tape (5) was not attached was attached to the tensiometer (6), and set so that the angle between the adhered surface of the cellophane tape (5) and the non-adhered surface (5a) was 90 degrees. The cellophane tape (5) was pulled off at a speed of 100 mm / min. At this time, the speed at which the tape (5) was peeled off and the stainless steel plate (3) to which the test sample (1) was attached were moved at the same speed, and the non-sticking surface (5a) of the cellophane tape (5) and the test sample (1) were moved. ) Plane was always 90 degrees. The force (F) required for peeling was measured by a tensiometer (6). (FIG. 1 (b)).

After the test, the peeled conductive film surface and the cellophane tape surface were examined. When the adhesive is present on both surfaces, the conductive layer was not destroyed, but the adhesive layer of the cellophane tape was destroyed, that is, the force (F) required for peeling off the adhesive strength Therefore, the strength of the conductive coating film is equal to or more than the value (F).

In this test, the upper limit of the strength of the adhesive was 6
Since it is N / 12 mm, what is indicated as 6 N / 12 mm in Table 1 is a case where the adhesive is present on both surfaces as described above, and the adhesion and the strength of the conductive film are 6 N / 12 mm or more. It represents that. If the value is smaller than this, it means that there is no adhesive on the surface of the conductive film and the conductive film is partially adhered to the surface of the cellophane tape. A value of 3 N / 12 mm or more is a practical level.

As a result of the 90 degree peel test, in Example 1, a force of 6 N / 12 mm was required to peel off the cellophane tape. When the coating film surface after the peel test was examined, the adhesive of the cellophane tape was adhered. When the adhesive surface of the peeled cellophane tape was examined, it was found to be adhesive. Therefore, the strength of the coating film was 6 N / 12 mm or more.

Example 2 A preliminary experiment was performed in the same manner as in Example 1 except that the pressure per unit length in the film width direction was changed to 660 N / mm and compression was performed. ATO film was obtained. In a preliminary experiment, without compressing and rotating the roll press machine,
Next, the pressure was released, and the length of the compressed portion in the longitudinal direction of the film was determined to be 1.9 mm. From the result, the pressure per unit area was 347 N / mm ² . In the following examples, the pressure per unit area was calculated in the same manner. The thickness of the ATO coating film after compression was 1.0 μm. The ATO film before compression used was the same as that prepared in Example 1, and the following Example 3 was used.
The same applies to Comparative Examples 1 to 6.

The electrical resistance of the compressed ATO film is 7
It was 5 kΩ. As a result of the 90 degree peel test, a force of 6 N / 12 mm was required to peel off the cellophane tape. When the coating film surface after the peel test was examined, the adhesive of the cellophane tape was adhered. When the adhesive surface of the peeled cellophane tape was examined, it was found to be adhesive. Therefore, the strength of the coating film was 6 N / 12 mm or more.

[Examples 3 to 6] A compressed ATO film was obtained in the same manner as in Example 1 except that the compression pressure was changed to the values shown in Table 1 and compression was performed. The electric resistance was measured, and a 90 degree peel test was performed.

Comparative Example 1 In Example 1, no compression was performed. That is, a physical property test was performed on the pre-compression ATO film of Example 1. A not compressed
The electric resistance of the TO film was 4,500 kΩ. 90
As a result of the degree peel test, it was 0.
A force of 8 N / 12 mm was required.

[0102]

[Table 1]

Table 1 shows the measurement results of Examples 1 to 6 and Comparative Example 1. Each of the conductive films of Examples 1 to 6,
The electric resistance was low, the coating strength was high, and the adhesion between the conductive film and the support film was excellent. From Examples 1 to 6,
The higher the pressing pressure, the better the conductivity, the stronger the coating film strength, the stronger the adhesion between the conductive film and the support film, and the adhesive of the cellophane tape remained on the conductive surface. . Further, the conductive films of Examples 1 to 6 were all excellent in transparency in terms of visible light transmittance. On the other hand, in the case of Comparative Example 1, since the compression step was not performed, the electric resistance value was high and the coating film strength was inferior to those of Examples 1 to 6.

In Examples 7 to 17 and Comparative Examples 2 to 4, ITO fine particles having lower electric resistance than ATO were used as conductive fine particles in order to obtain a transparent conductive film for use in an electroluminescent panel electrode. It is an example.

Example 7 300 parts by weight of ethanol was added to 100 parts by weight of ITO fine particles (manufactured by Dowa Mining Co., Ltd.) having a primary particle size of 10 to 30 nm, and the medium was dispersed as zirconia beads by a disperser. The obtained coating liquid is 50 μm
The composition was applied on a thick PET film using a bar coater, and dried by sending warm air at 50 ° C. The resulting film is hereinafter referred to as a pre-compression ITO film. I
The thickness of the TO-containing coating film was 1.7 μm.

In the same manner as in Example 1, using a roll press, the ITO film before compression was pressed at a pressure of 1000 N / mm per unit length in the film width direction, a pressure of 500 N / mm ² per unit area, and 5 m / m2. Compressed at a feed rate of 1 minute to obtain a compressed ITO film. ITO after compression
The thickness of the coating film was 1.0 μm. The electrical resistance of the compressed ITO film was 3 kΩ. From the result of the 90 degree peel test, the coating film strength was 6 N / 12 mm or more.

Examples 8 to 12 Compressed ITO films were obtained in the same manner as in Example 7 except that the compression pressure was changed to the values shown in Table 2 and compression was performed. The electric resistance was measured, and a 90 degree peel test was performed.

Comparative Example 2 In Example 7, no compression was performed. That is, a physical property test was performed on the ITO film before compression in Example 7. I not compressed
The electric resistance of the TO film was 340 kΩ. As a result of the 90 degree peel test, it was 1.2 to remove the cellophane tape.
A force of N / 12 mm was required.

Example 13 A compressed ITO film was obtained in the same manner as in Example 8, except that the feed speed during compression was changed to 2.5 m / min. The electric resistance was measured, and a 90 degree peel test was performed.

Example 14 Polyvinylidene fluoride (PVDF: density 1.8 g / cm ³ ) was used as a resin.
A resin solution was prepared by dissolving 100 parts by weight of PVDF in 900 parts by weight of NMP. IT with primary particle size of 10-30nm
O fine particles (density: 6.9 g / cm ³ , Dowa Mining Co., Ltd.)
100 parts by weight), 50 parts by weight of the resin solution and NMP
375 parts by weight were added, and the medium was dispersed as zirconia beads using a disperser. The obtained coating solution is applied to a 50 μm thick P
It was applied on an ET film using a bar coater and dried (100 ° C., 3 minutes) to obtain an ITO film before compression.
(The volume of PVDF was 19 when the volume of the ITO fine particles was 100.) In the same manner as in Example 1, the film was pressed at a pressure per unit length in the film width direction of 66 using a roll press.
0 N / mm, pressure 347 N / mm ² per unit area,
Compressed at a feed speed of 5 m / min to obtain a compressed ITO film. The thickness of the ITO coating film after compression was 1.0 μm. The electric resistance was measured, and a 90 degree peel test was performed.
The result of the 90 degree peel test was 5 N / 12 mm.
This was due to the fact that PVDF oozed out to the surface of the coating film due to compression at high pressure, and the adhesion of the cellophane tape to the surface of the coating film became low, and the coating film was not broken. Therefore, the coating film strength was 5 N / 12 mm or more.

Examples 15 to 17 A compressed ITO film was obtained in the same manner as in Example 14, except that the compression pressure was changed to the values shown in Table 2 and compression was performed. The electric resistance was measured, and a 90 degree peel test was performed.

Comparative Example 3 In Example 14, no compression was performed. That is, a physical property test was performed on the ITO film before compression in Example 14. The electrical resistance of the uncompressed ITO film was 320 kΩ. 9
As a result of the 0 degree peel test, it took 1 to remove the cellophane tape.
A force of N / 12 mm was required.

[Comparative Example 4] PVD was added to 900 parts by weight of NMP.
F100 parts by weight were dissolved to obtain a resin solution. ITO fine particles having a primary particle size of 10 to 30 nm (manufactured by Dowa Mining Co., Ltd.)
100 parts by weight, 1000 parts by weight of the resin solution and NMP
900 parts by weight were added, and the medium was dispersed as zirconia beads using a disperser. The obtained coating solution is applied to a 50 μm thick P
It was applied on an ET film using a bar coater and dried (100 ° C., 3 minutes) to obtain an ITO film. The thickness of the ITO coating film was 1.0 μm. Measure the electrical resistance and
A 0 degree peel test was performed (the volume of the ITO fine particles was 100
And the volume of PVDF was 383). 90
The result of the degree peel test was 3.4 N / 12 mm.
This is because PVDF oozed out to the surface of the coating film due to the large amount of the resin, and the adhesion of the cellophane tape to the surface of the coating film became low, and the coating film was not broken. Therefore, the coating film strength was 3.4 N / 12 mm or more.

[0114]

[Table 2]

Table 2 shows the measurement results of Examples 7 to 17 and Comparative Examples 2 to 4. Each of the conductive films of Examples 7 to 17 had a low electric resistance value, a high coating strength, and was excellent in adhesion between the conductive film and the support film. Example 7-
12 and Examples 14 to 17, the higher the pressing pressure, the better the conductivity, the stronger the coating film strength, the stronger the adhesion between the conductive film and the support film, and the adhesive of the cellophane tape becomes conductive. It was so much left on the surface. As the conductive fine particles, ITO was more excellent in conductivity than ATO. More excellent conductivity was obtained with a conductive film containing no resin than with a conductive film containing a resin. Also,
All of the conductive films of Examples 7 to 17 were excellent in transparency in terms of visible light transmittance.

On the other hand, those of Comparative Examples 2 and 3
Since the compression step was not performed, each of Examples 7 to 12 was used.
And 14 to 17, the electrical resistance was higher and the coating film strength was inferior. In Comparative Example 4, a large amount of binder resin was used so that a coating film could be formed without compression as in the conventional case. Since the binder resin was used in a large amount, the strength of the coating film was sufficient, but the electric resistance was high.

In Examples 18 to 20 described below, tungsten oxide (WO ₃ ) fine particles, titanium oxide (TiO ₂ ) fine particles, and aluminum oxide (Al ₂ O ₃ ) were used as inorganic fine particles.
This is an example in which an inorganic material film is manufactured using fine particles.

[Embodiment 18] This embodiment is an example in which WO ₃ fine particles are used for an electrochromic display device. Ethanol 400 parts by weight of a primary particle size of the WO ₃ particles 100 parts by weight of 50 to 100 nm, were dispersed by a dispersing machine media as zirconia beads. The obtained coating liquid was applied on a PET film having a thickness of 50 μm using a bar coater, and dried by sending warm air at 50 ° C.
The resulting film is hereinafter referred to as a pre-compression WO ₃ film. The thickness of the WO ₃ -containing coating film was 1.0 μm.

In the same manner as in Example 1, using a roll press, the WO ₃ film before compression was pressed at a pressure of 1000 N / mm per unit length in the film width direction and at a pressure of 500 N / mm ² per unit area, 5 m / Min at a feed rate of / min to obtain a compressed WO ₃ film. WO ₃ after compression
The thickness of the coating film was 0.6 μm.

The obtained WO ₃ film was subjected to a 90 ° peel test as in the case of the conductive film, and the state of the coating film was examined. A force of 6 N / 12 mm was required to peel off the cellophane tape. When the coating film surface after the peel test was examined, the adhesive of the cellophane tape was adhered. When the adhesive surface of the peeled cellophane tape was examined, it was found to be adhesive. Therefore, the strength of the coating film was 6 N / 12 mm or more.

[Embodiment 19] This embodiment relates to a photocatalyst film.
As an alternative, TiO_TwoThis is an example using fine particles. Primary particle size
Is 30-70 nm TiO_Two100 parts by weight of fine particles
Add 900 parts by weight of knoll and add zirconia beads to the media.
And dispersed with a dispersing machine. The obtained coating liquid is 50 μm
Coating on thick PET film using a bar coater
Then, it was dried by sending warm air at 50 ° C. The resulting film
Is hereinafter referred to as TiO before compression. _TwoCalled film.
TiO_TwoThe thickness of the containing coating film was 0.7 μm.

In the same manner as in Example 1, using a roll press, the TiO ₂ film before compression was pressed at a pressure of 1000 N / mm per unit length in the film width direction and at a pressure of 500 N / mm ² per unit area of 5 m. / Min at a feed rate of / min to obtain a compressed TiO ₂ film. T after compression
The thickness of the iO ₂ coating was 0.5 μm.

The obtained TiO ₂ film was subjected to a 90 ° peel test as in the case of the conductive film, and the state of the coating film was examined. A force of 6 N / 12 mm was required to peel off the cellophane tape. When the coating film surface after the peel test was examined, the adhesive of the cellophane tape was adhered. When the adhesive surface of the peeled cellophane tape was examined, it was found to be adhesive. Therefore, the strength of the coating film was 6 N / 12 mm or more.

[Embodiment 20] This embodiment is an example in which Al ₂ O ₃ fine particles are used as a catalyst film. Ethanol 400 parts by weight of a primary particle size of the Al ₂ O ₃ fine particles 100 parts by weight of 5 to 20 nm, dispersed in a dispersing machine media as zirconia beads. The obtained coating liquid is 50 μm
The composition was applied on a thick PET film using a bar coater, and dried by sending warm air at 50 ° C. The resulting film is hereinafter referred to as an uncompressed Al ₂ O ₃ film. The thickness of the Al ₂ O ₃ -containing coating film was 1.2 μm.

In the same manner as in Example 1, the roll press was
Using the pre-compression Al_TwoO_ThreeFilm width
Pressure per unit length in the direction 1000N / mm, unit area
Pressure per hit 500N / mm^TwoAt a feed rate of 5m / min
Compressed and compressed Al_TwoO _ThreeA film was obtained. After compression
Al_TwoO_ThreeThe thickness of the coating film was 0.8 μm.

The obtained Al ₂ O ₃ film was subjected to a 90 ° peel test as in the case of the conductive film, and the state of the coating film was examined. A force of 6 N / 12 mm was required to peel off the cellophane tape. When the coating film surface after the peel test was examined, the adhesive of the cellophane tape was adhered. When the adhesive surface of the peeled cellophane tape was examined, it was found to be adhesive. Therefore, the strength of the coating film was 6 N / 12 mm or more.

In the above embodiment, AT fine particles were used as the inorganic fine particles.
An example was shown in which an inorganic functional film was prepared using O fine particles, ITO fine particles, WO ₃ fine particles, TiO ₂ fine particles, and Al ₂ O ₃ fine particles. Various inorganic functional films can be produced using inorganic fine particles having various properties in the same manner as in the above-described embodiment.

Examples 21 to 24 are more preferred examples of the transparent conductive film of the present invention. [Example 21] 1. Formation of compressed layer of ITO fine particles 300 parts by weight of ethanol was added to 100 parts by weight of ITO fine particles (manufactured by Dowa Mining Co., Ltd.) having a primary particle size of 10 to 30 nm, and the medium was dispersed as zirconia beads using a dispersing machine. The obtained coating solution was applied on a PET film having a thickness of 50 μm using a bar coater, and dried by sending warm air at 50 ° C. The obtained film is hereinafter referred to as a pre-compression ITO film (A). The thickness of the ITO-containing layer before compression was 1.7 μm.

First, a preliminary experiment for confirming the compression pressure was performed. Room temperature (23 ° C.) using a roll press equipped with a pair of 140 mm-diameter metal rolls (having a roll surface subjected to hard chrome plating) without rotating the rolls and without heating the rolls Then, the ITO film (A) before compression was sandwiched and compressed. At this time, the pressure per unit length in the film width direction is 660 N / mm
Met. Next, the pressure was released, and the length of the compressed portion in the longitudinal direction of the film was 1.9 mm. From this result, it can be said that compression was performed at a pressure of 347 N / mm ² per unit area.

Next, the same pre-compressed ITO film (A) as that used in the preliminary experiment was sandwiched between metal rolls and compressed under the above conditions, and the rolls were rotated and compressed at a feed speed of 5 m / min. Thus, an ITO film (B) on which a compressed layer of ITO fine particles was formed was obtained. The thickness of the ITO compression layer was 1.0 μm. Examples 22 and 2 below
Also in 3, the same ITO film (B) was used for impregnation with a transparent substance.

(Measurement of Electric Resistance Before Impregnation) The film on which the ITO compressed layer was formed was cut into a size of 50 mm × 50 mm. A tester was applied to two diagonal corners to measure the electric resistance, and it was 4 kΩ. (Measurement of haze before impregnation) Haze meter (TC-H3
The haze was measured using a DPK type (manufactured by Tokyo Denshoku Technical Center) and found to be 6%.

[0132] 2. Impregnation of Transparent Material (Preparation of Masking Film) A PET film having a thickness of 10 μm is sandwiched between roll presses, and the pressure per unit length in the width direction is set to 50 N / mm.
Compressed at a feed rate of minutes. By this operation, the PET film was charged. As shown in FIG. 2, 40 m in the width direction (w ₁ ) was placed almost at the center in the width direction of the charged PET film.
A rectangular hole (11a) having a size of mx 60 mm in the longitudinal direction (l ₁ ) was made. Hereinafter, this was used as a masking film (11).

(Impregnation of Transparent Substance) A silicone resin was used as an impregnation substance. Silicone varnish (TSR-14
5, 50 parts by weight of ethanol and 1.5 parts by weight of a curing catalyst (CR-15, manufactured by GE Toshiba Silicone Co., Ltd.) are added to 100 parts by weight of GE Toshiba Silicone Co., Ltd., solid content concentration 60% by weight. An impregnation liquid was obtained. The above 1. ITO obtained in
The above-mentioned charged PE is placed on the ITO compression layer surface of the film (B).
A T film (11) was applied and masked. The impregnating liquid described above was applied to the masked ITO film (B) using a bar coater, the masking film (11) was removed, and dried by sending 60 ° C warm air. Next, at 100 ° C,
The silicone resin was cured for one hour. As shown in FIG. 3, at the same time that the ITO compressed layer (12) was impregnated with the silicone resin, a protective layer (13) having a thickness of 4 μm was formed on the ITO compressed layer (12).

(Measurement of Electric Resistance After Impregnation) The impregnated ITO film was subjected to I
The sheet was cut to a size of 50 mm in the width direction (w ₂ ) × 50 mm in the longitudinal direction (l ₂ ) so as to include both end portions (12a) and (12b) where the surface of the TO compression layer (12) was exposed. Thus, a transparent conductive film sample of the present invention as shown in FIG. 4 was obtained (in FIG. 4, the support (14)). A tester was applied to two corners at diagonal positions where the protective layer (13) was not formed, and the electrical resistance was measured. (Measurement of Haze after Impregnation) The haze of the portion (13) subjected to the impregnation treatment was measured and found to be 2%.

Example 22 Example 21 was used as an impregnating substance.
Was changed to an acrylic resin. To 100 parts by weight of an acrylic resin solution (103B, manufactured by Taisei Kako Co., Ltd., solid content concentration: 50% by weight), 82 parts by weight of toluene was added to obtain an impregnating liquid. The same ITO used in Example 21
Masking was performed on the ITO compression layer surface of the film (B) in the same manner as in Example 21. The impregnating liquid described above was applied to the masked ITO film (B) using a bar coater, the masking film was removed, and hot air at 60 ° C. was sent to dry. At the same time as the ITO compressed layer was impregnated with the acrylic resin, a protective layer having a thickness of 3.5 μm was formed on the ITO compressed layer. The electrical resistance of the impregnated ITO film was 4 kΩ. The haze of the impregnated part is 4
%Met.

Example 23 Example 22 was used as an impregnating substance.
Changed the type of acrylic resin. Further, the masking film in the impregnation operation was changed to a PET film having a thickness of 15 μm. To 100 parts by weight of an acrylic resin solution (1BR-305B, manufactured by Taisei Kako Co., Ltd., solid content concentration: 39.5% by weight), 100 parts by weight of toluene was added to obtain an impregnating liquid. ITO of the same ITO film (B) used in Example 21
15 μm charged on the surface of the compression layer in the same manner as in Example 21
An m-thick PET film was applied and masked. The impregnating liquid was applied to the masked ITO film (B) using a bar coater, the masking film was removed, and hot air at 60 ° C. was sent to dry. At the same time as the acrylic resin was impregnated into the ITO compressed layer, a protective layer having a thickness of 2.5 μm was formed on the ITO compressed layer. The electrical resistance of the impregnated ITO film was 4 kΩ. The haze of the impregnated portion was 4%.

[Comparative Example 5] I before compression in Example 21
The TO film (A) was impregnated without compression in the same manner as in Example 21. While the ITO layer was impregnated with the silicone resin, 3.0 μm
An m-thick protective layer was formed. The electrical resistance of the impregnated ITO film was 210 kΩ. The haze of the impregnated portion was 4%.

[Comparative Example 6] I before compression in Example 21
The TO film (A) was directly impregnated without compression in the same manner as in Example 22. At the same time as the acrylic resin is impregnated in the ITO layer, 3.0 μm
A thick protective layer was formed. The electric resistance of the impregnated ITO film was 340 kΩ. The haze of the impregnated portion was 7%.

[Comparative Example 7] I before compression in Example 21
The TO film (A) was impregnated without compression in the same manner as in Example 23. At the same time as the acrylic resin is impregnated into the ITO compression layer, 2.0
A protective layer having a thickness of μm was formed. Impregnated ITO
The electrical resistance of the film was 340 kΩ. The haze of the impregnated portion was 7%.

Example 24 The thickness of the ITO-containing layer of the uncompressed ITO film (A) in Example 23 was 2.6 μm.
m, except that ITO was changed to m.
An ITO film (C) having a 1.5 μm-thick compressed layer was obtained. The electrical resistance of the ITO film (C) was 3 kΩ. The haze was 7%.

In the same manner as in Example 23, the ITO film (C) was impregnated. At the same time as the acrylic resin was impregnated into the ITO compression layer, a protective layer having a thickness of 3.0 μm was formed on the ITO layer. The electrical resistance of the impregnated ITO film was 3 kΩ. The haze of the impregnated portion was 5%.

[0142]

[Table 3]

Table 3 shows the results of Examples 21 to 24 and Comparative Examples 5 to 7. Each of the conductive films of Examples 21 to 24 was excellent in low electric resistance value and small haze. It can be seen that the haze was improved by the impregnation of the transparent substance without adversely affecting the electric resistance value. It is considered that the reason why the degree of haze improvement was large in Example 21 was that silanol groups were present in the silicone resin, and the silicone resin had good affinity with ITO and was more densely impregnated. When the same 90 degree peel test as in Example 1 was performed on the conductive films of Examples 21 to 24, none of the coating films was broken or peeled off. On the other hand, in Comparative Examples 5 to 7, since the compression operation was not performed, the electric resistance was high and the performance was insufficient as a conductive film.

The embodiments described above are merely illustrative in every respect and should not be construed as limiting. Furthermore, all modifications belonging to the equivalent scope of the claims are within the scope of the present invention.

[0145]

According to the present invention, a functional film can be obtained by a simple operation of applying a paint containing functional fine particles to a support and then compressing it. The functional film according to the present invention has sufficient mechanical strength, and the harmful effects of the binder resin in the conventional coating method are eliminated, and as a result, the intended function is further improved.

According to the present invention, a transparent conductive film can be obtained by a simple operation of applying a conductive paint to a support and then compressing the support. The transparent conductive film according to the present invention has excellent conductivity and transparency. Further, it has sufficient mechanical strength, strong adhesion between the conductive film and the support, and can be used for a long time.

According to the present invention, a transparent conductive film can be obtained by a simple operation of applying a conductive paint to a support, compressing the support, and then preferably impregnating the support with a transparent substance. The preferred transparent conductive film according to the present invention has excellent conductivity and very good transparency. Further, the adhesion between the conductive film and the support is strong, so that the conductive film can be used for a long time.

Further, according to the method of the present invention, it is possible to cope with an increase in the area of the conductive film, the apparatus is simple, the productivity is high, and various functional films including a transparent conductive film can be manufactured at low cost.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a 90-degree peel test in an example.

FIG. 2 is a plan view schematically showing a masking film used in Examples 21 to 24.

FIG. 3 is a plan view schematically illustrating an example of a transparent conductive film of the present invention manufactured in Examples 21 to 24.

FIG. 4 is a perspective view schematically showing an example of the transparent conductive film of the present invention produced in Examples 21 to 24.

[Explanation of symbols]

 (1): Test sample with conductive film formed (1b): Support film (1a): Conductive film (2): Double-sided tape (3): Stainless steel plate (4): Cellophane tape for fixing (5): Cellophane Tape (5a): Cellophane tape non-adhered surface (6): Tensiometer (11): Masking film (11a): Hole in masking film (12): Compressed conductive fine particle layer (13): Protective layer (14): Support Body film

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B32B 9/00 B32B 9/00 A G02F 1/15 505 G02F 1/15 505 H01B 5/14 H01B 5/14 A 13/00 503 13/00 503B F-term (reference) 2K001 BB01 BB16 4D075 BB05Z CA21 CA45 DA04 DB31 DC21 EA02 EC02 4F100 AA25B AA28B AA33B AE01B AK01A AK42 AT00A BA02 CA21B DE01B01 J02J08J01J05J01J05J05J02J22J01J04J02J822JEJBJJEJBJ01 JN01B JN06B JN13B 5G307 FA01 FA02 FB01 FC10 5G323 BA02 BB01 BC03

Claims (16)

[Claims] 1. A functional film comprising a compressed layer of functional fine particles obtained by compressing a layer containing functional fine particles formed by coating on a support. 2. The functional film according to claim 1, wherein the functional fine particle-containing layer is formed by applying a liquid in which functional fine particles are dispersed on a support and drying the liquid. 3. The functional film according to claim 1, wherein the functional fine particles are selected from inorganic fine particles. 4. The compressed layer of the functional fine particles has a compression ratio of 44 N /
It is obtained by compressing in mm ² or more compression strength, functional membrane according to any one of claims 1 to 3. 5. A conductive film, a magnetic film, a ferromagnetic film, a dielectric film,
The film is selected from a ferroelectric film, an electrochromic film, an electroluminescence film, an insulating film, a light absorption film, a light selective absorption film, a reflection film, an antireflection film, a catalyst film, and a photocatalyst film. Or the functional film according to item 1. 6. The functional film according to claim 1, wherein the support is a resin film. 7. The functional film according to claim 1, wherein the functional fine particles are conductive fine particles and have a function as a conductive film. 8. The method according to claim 1, wherein the functional fine particles are conductive fine particles, and a compressed layer of the functional fine particles is impregnated with a transparent substance to have a function as a transparent conductive film. The functional film according to the above item. 9. The conductive fine particles are made of tin oxide, indium oxide, zinc oxide, cadmium oxide, antimony-doped tin oxide (ATO), fluorine-doped tin oxide (FTO), tin-doped indium oxide (ITO), and aluminum-doped oxide. The functional film according to claim 7 or 8, wherein the functional film is a conductive inorganic fine particle selected from the group consisting of zinc (AZO). 10. A liquid in which functional fine particles are dispersed is coated on a support and dried to form a functional fine particle-containing layer. Thereafter, the functional fine particle-containing layer is compressed to form a compressed layer of functional fine particles. A method for producing a functional film, comprising forming. 11. The layer containing functional fine particles having a thickness of 44 N / m.
The method for producing a functional film according to claim 10, wherein the functional film is compressed with a compressive force of m ² or more. 12. The method for producing a functional film according to claim 10, wherein the functional fine particle-containing layer is compressed at a temperature at which the support does not deform. 13. The method for producing a functional film according to claim 10, wherein the functional fine particle-containing layer is compressed using a roll press. 14. The functional film according to claim 10, wherein the functional fine particles are conductive fine particles, and the liquid in which the functional fine particles are dispersed contains no resin. Manufacturing method. 15. The method according to claim 10, wherein the functional fine particles are conductive fine particles, and further include impregnating a transparent substance in a formed compressed layer of the functional fine particles. The method for producing the functional film according to the above. 16. A functional film in which a functional fine particle-containing coating layer is formed on a support.